Slow Rendering
by Andy Footman
on
Jun 26, 2008 at 12:47:22 pm
Hi,
I've had a good look around at various forums trying to find the answers I need to my slow rendering speeds and it's about time I posted my own thread.
I'm running:
After Effetcts 7
Dell Precision T7400
Intel Xeon CPU E5430@ 2.66ghz
4GB Ram
Nvidia 8800 ultra card
I've altered the BCD to allow 3GB of RAM for applications also.
I'm trying to compile my first HDV recorded project. I got the data off my Canon HV20 using HDVsplit and subsequently have now got about 10GB worth of data split over about 40 files in m2t format which opens fine. These are all stored on a firewire external hard drive. I've compiled the files into a nice sequence with no real amazing effects apart from a straight forward gradient wipe between clips. The total composition length is about 45mins. At first I tried rendering to Mpeg-dvd and it crashed overnight. Since then I've done a fair bit of reading and have since tried rendering using a demo of Gridiron Nucleo to a quicktime format, along with trying avi formats, with no real change in render times. If I use the standard AE renderer I can force it to purge the cache every 30 frames which I think will stop it running out of RAM and crashing but the CPU usage is still only about 25%. Using Nucleo it starts off using lots of cpu power but as the RAM usage ramps up to about 3GB the CPU goes right down to about an average of 15% total. Sometimes 2% per CPU. I've tried saving the file to a different drive other than the external because I thought all that traffic going to the one firewire drive couldn't be good i.e. source material coming from it and render saved to it, with no real change. I'm not viewing the clips whilst it's rendering also (caps lock).
Several questions:
1-Am I killing my machine by loading so much source material into one project? Should I split the project up into smaller chunks?
2-Do I need to convert the m2t files before importing them into AE?
3-Am I just being impatient? Should I just let it render using the standard AE renderer along with the purge every 30 frames secret option. If that's the case why isn't it using more CPU. I understand the CPU's can only process data that is being supplied to them, so if the RAM is fully being used the CPU's are doing the best they can. Is that why the Nucleo CPU usage goes right down also?
Any info would be a great help. Sorry for the long post!!
Andy
Re: Slow Rendering by Dave LaRonde on Jun 26, 2008 at 3:34:26 pm
This is a common lament. Read on.....
Dave's Stock Answer #1:
If the footage you imported into AE is any kind of the following -- Native HDV, MPEG1, MPEG2, mp4, m2t, H.261 or H.264 -- you need to convert it to a different codec.
These kinds of footage use temporal, or interframe compression. They have keyframes at regular intervals, containing complete frame information. However, the frames in between do NOT have complete information. Interframe codecs toss out duplicated information.
In order to maintain peak rendering efficiency, AE needs complete information for each and every frame. But because these kinds of footage contain only partial information, AE freaks out, resulting in a wide variety of problems.
Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA
Re: Slow Rendering by Andy Footman on Jun 26, 2008 at 4:34:49 pm
Thanks for the replies guys. It's the first time I've taken my own footage from an HDV source and so I was suspect. I'll look at converting the source footage before I touch AE again.
I did try saving my file as a premiere project but it didn't want to open. I'm guessing that could be to do with m2t files also. I know it's simple at the moment but I would like to do a little bit more with it but not alot so maybe I should look at something else. It's just that I know and have AE and didn't want to add another software tool like final cut or anything into the mix. I hope converting the files from m2t will help first.
Re: Slow Rendering by Jan Sherlink on Jun 26, 2008 at 3:40:24 pm
At first,
there's no reason at all why you should use After Effects.
A 45 min comp with wipes only... you should be using Final Cut, Premiere, Vegas, MediaStudio..... whatever... but not AE.
You'll have realtime playback for hours and hours without limitations.
The "Purge Cache" won't help either in AE.
AE doesn't like m2t or mpeg-like files but likes uncompressed or Mjpg compression.
so,
the fastest and only good thing to do would be to Shut Down AE, start up your NLE and start the project over. If you Have Premiere, you can import your AE-comp, so no time is lost at all :-)
